Poultry and livestock are often confined in houses specifically designed to contain them while they are grown to marketable size. Some of these houses have large screened openings in the walls that are typically covered with heavy fiberglass curtains that can be automatically or manually opened when necessary to provide adequate ventilation and control the temperature for the animals. During normal operations the curtains are closed and electric ventilating fans are used to contantly remove the carbon dioxide and heat generated by the animals and continuously provide the fresh air necessary for the animals good health. The curtains are partially opened and closed as necessary to maintain the proper temperature for the animals. A power failure in the electric ventilation fans or an unusual increase in the inside temperature must be promptly detected and the alternate emergency ventilation system automatically activated which usually consists of instantly opening all of the curtains. Cross ventilation through the screened openings will then provide emergency ventilation for the animals.
The quicker the problem is solved the less stress on the animals, therefore it is imperative to quickly notify the maintenance personnel whenever a problem occurs.
In the newer poultry and animal confinement houses the curtains are maintained closed and in some houses are even replaced with solid louver pan33s that are maintained closed. Air is constantly drawn through the "tunnel house" and temperature is controlled by heaters or by dripping water through filter panels or spraying a fine mist for cooling. In the tunnel house, air flow must be maintained evenly throughout the house. When power is lost and emergency ventilation is called for, all the curtains or the louvers must be opened at the same time. Even if power is not out and one of the curtains or a louver inadvertently opens, this condition must be instantly sensed and all the curtains or louvers opened instantly to prevent the shunting effects of the air flow that will cause disasterous effects on the animals. Maintenance personnel must also be notified immediately to correct the problem.
Several prior patents disclose various methods and devices for automatically opening the curtains during an emergency. For example, U.S. Pat. No. 3,429,298 issued Feb. 25, 1969 discloses a poultry house and an associated curtain raiser which includes an electric motor controlled by a relay, a thermostat and a timer to operate the building curtains through a system of controlled cables. U.S. Pat. No. 3,915,377 discloses a device which, upon the occurrence of a power failure, activates a circuit containing a battery which heats a nichrome wire. A nylon cord extends from the apparatus which holds the curtains in a raised position and passes closely adjacent to the nichrome wire which burns through the cord, releases the curtains and allows them to drop, thus providing emergency ventilation. U.S. Pat. No. 4,605,162 discloses a bimetal strip mounted to a mechanical arm and inserted into a power resistor used as a heater. In arrangements of this type, the time delay following power failure cannot be determined with any degree of accuracy and the energy required is substantial.
U.S. Pat. No. 5,205,785 to the present applicant discloses a unique concept for controlling the normally closed ventilating means in a poultry building or the like in response to a power failure in the building ventilating system. In the utilization of devices manufactured to the specifications disclosed in the above patents I have developed several improvements that are herein disclosed.
None of the above patents addressed the problem of the air flow being shunted in a tunnel ventilated building, the need for an over temperature sensor such as a thermostat, the need to supply a regulated voltage to maintain the charge on the battery, the control of more than one curtain or louver with a single electronic unit, nor the need to immediately notify maintenance personnel whenever a problem occurs. The invention described herein addresses these problems and provides a system where more than one curtain or louver can be monitored and controlled by a single electronic unit that reliabily releases the ventilation means upon a power failure, an out of tolerance temperature condition or the accidental opening of any one of the controlled curtains or louvers, and provides a regulated charging voltage to the battery, and provides a means to automatically send an alarm to notify maintenance personnel upon the sensing of any problem.